Case

During a cardiac surgery on a 38 year old female patient, the surgeon detaches the left internal thoracic artery and connects it to a coronary artery in a bypass surgery (a LITA procedure, left internal thoracic artery coronary bypass). The surgeon is unconcerned about blood supply to the chest wall or the breast.

Question 2/2 - Which vessels(s) directly 'take over' supplying the chest wall?

Click on your selected option(s) below  (correct = 1, possible = 2, over-thinking = 3+)

Case Complete

Incorrect. The subclavian supplies the internal thoracic artery, so blood flow from the subclavian artery has been redirected to the coronary vessels by the internal thoracic artery bypass.   

Incorrect. The anterior intercostal arteries are normally supplied by the internal thoracic artery, which has been detached for the coronary bypass. Thus, the normal supply to these vessels has been removed.   

Mostly incorrect. While there are a small number of anastomoses between tissues of the left and right sternum, this really isn't sufficient to reperfuse the left anterior thorax from the right side. In general, left to right anastomoses are very limited to non-existent.

Incorrect. The musclophrenic artery is a terminal branch of the internal thoracic artery (which branches into the superior epigastric and musclophrenic arteries at the costal margin). Blood can retrograde flow in this vessel from abdominal supply, but since the internal thoracic artery has been detached that flow cannot reach the anterior thoracic wall.

Correct! The posterior intercostal arteries anastomose with the anterior intercostal arteries forming the major supply to the anterior thoracic wall. When there is a pressure drop in the anterior intercostal arteries (due to the removal of the internal thoracic artery which supplies the anterior intercostal arteries), blood flows into the anastomosis area from the posterior intercostal arteries rebalancing tissue perfusion pressure. This happens essentially immediately as pressure rebalances in the vasculature bed within a few heartbeats.

Incorrect. The aorta is the original supply to all vasculature of the body, but the aorta does not directly connect to the anterior thoracic wall (there are named vessels between the aorta and the anterior wall).   

Partially correct. The lateral thoracic artery supplies the lateral side of the breast and there are anastomoses to the medial side, so some of the blood reperfuses the anterior thoracic territory of the internal thoracic artery can come from the lateral thoracic artery, but it's not the primary vessel that takes over the supplying the region.